GENERAL DESCRIPTION

The TC7135 4-1/2 digit analog-to-digital converter (ADC) offers 50 ppm (1 part in 20,000) resolution with a maximum nonlinearity error of 1 count. An auto-zero cycle reduces zero error to below 10 µV and zero drift to 0.5 µV/°C. Source impedance errors are minimized by a 10 pA maximum input current. Roll-over error is limited to ±1 count.

FEATURES

■ Low Roll-Over Error ......................... ±1 Count Max

■ Guaranteed Nonlinearity Error ........ ±1 Count Max

■ Guaranteed Zero Reading for 0V Input

■ True Polarity Indication at Zero for Null Detection

■ Multiplexed BCD Data Output

■ TTL-Compatible Outputs

■ Differential Input

■ Control Signals Permit Interface to UARTs and

µProcessors

■ Auto-Ranging Supported With Overrange and

Underrange Signals

■ Blinking Display Visually Indicates Overrange

Condition

■ Low Input Current ............................................. 1 pA

■ Low Zero Reading Drift ............................... 2 µV/°C

■ Interfaces to TC7211A (LCD) and TC7212A (LED)

Display Drivers

■ Available in DIP and Surface-Mount Packages